Many types of lighting products use coated substrates as a light reflector. For example, fluorescent lamps often are fabricated using a sheet metal reflector that has been coated with a white coating. The coating protects the substrate from degradation (e.g., corrosion) as well as serving as the light reflector. Consequently, obtaining coatings with high reflectivity is a long sought goal. In general, the pigment loading of a coating (e.g., the TiO2 loading in the case of a white coating) can affect the reflectivity, with the higher reflectivity levels being achieved at high pigment loading. Unfortunately, such pigments are quite expensive and the increased loading levels required in the conventional coatings makes the coatings expensive. To date, manufacturers have been unable to achieve high reflectivity at reasonable cost.
Many other types of coated articles (e.g., window blinds, rain gutters and downspouts) are formulated to have high reflectivity and/or whiteness. In the case of rain gutters and downspouts, large shares of the products are made in a white color. Unfortunately, these products often lose their pleasing white color after exposure to the outdoor elements. Also, the initial reflectivity is less than desired (i.e., the reflectivity value is lower than desired) or the reflectivity comes at too high a cost (i.e., the pigment loadings are too expensive for the market). In the case of window blinds (e.g., Venetian blinds) it is common to make the blinds using coated metal substrates. There is a strong desire to increase the range of colors available from the color spectrum. In particular, there is a desire for “brighter” colors. Unfortunately, the brighter colors are not available because of limits on reflectivity of the available coatings.
From the foregoing, it will be appreciated that what is needed in the art is a coating (preferably a low cost coating) that has extremely high reflectivity when applied to a substrate. Such coatings, articles made using these coatings, and methods for preparing the coatings and articles are disclosed and claimed herein.